DK143721B - PROCEDURE AND OVEN FOR DISPOSAL OF WASTE - Google Patents

Description

(19) DENMARK VjS /

^ (> 2) SUBMISSION WRITING out 1U3721 B

DIRECTORATE OF THE PATENT AND TRADEMARKET SYSTEM

121) Application No. 487/77 | B „| nt.a, F 23 6 5/04 (22) Filing date 4 Feb. 1977 (24) Race day 4 Feb 1977 (41) Aim. available Aug. 6 1977 (44) Presented 28th eep. 1981 (86) International application no.

(86) International filing day (85) Continuation day - (62) Stock application no.

(30) Priority Feb 5 1976, 26044C9, DE

(71) Applicant HEINZ MALLER, D-51 72 Linnich / Tetz, DE.

(72) Inventor Heinz Mallek, DE: Werner Jablonski, DE: Peter _Pelzer,

THE

(74) Associate Engineer Hofman-Bang & Bout ard.

(54) Process and furnace for incineration of waste.

The invention relates to a method of the kind set forth in claim 1. By this method of combustion described in GB patent 1,556,125 and the incinerator described in the same patent, the waste flows from an inner cone, which together with the wall of the furnace forms a narrow passage for the waste, into the combustion chamber in which the waste is burned by means of burners. from which external fuel is supplied. From below, fresh air CD is fed through the inner cone, which is designed as a grate, into the waste column above the narrow place.

CM

The gas formed by drying, degassing and gasifying the waste-00 is suctioned from the top of the shaft and passed through plants for in-treatment of the gas, e.g. a purification plant, after which the treated gas is then fed 14 2 143721 again to the incinerator. This known combustion method is uneconomical insofar as it requires the addition of supplementary fuel, e.g. oil for waste incineration. In addition, the method requires a combustion plant which is complicated and expensive, especially in terms of gas treatment and control.

SUMMARY OF THE INVENTION It is an object of the invention to provide a readily achievable process of the present kind for the incineration of waste, in which the calorific value of the waste is optimally utilized for the incineration of the waste and where even with the supply of varying amounts of waste a uniform incineration is ensured and the necessary temperature is maintained. by simple means. This is achieved by the characterizing part of claim 1. By means of the process according to the invention, in which the material to be incinerated - the dried, heated and degassed waste and the waste gas formed in the degassing - as well as the fresh air supplied for the maintenance of the combustion can be supplied in one and the same place, namely the narrow place. simple conditions, namely by regulating the supply of fresh air and / or by changing the rate at which the waste is supplied to the narrow place, provide optimum conditions for the combustion process. The gas produced by the drying and degassing of the waste, so-called dry distillation gas, is conducted by the method according to the invention - as this waste gas is directed downwards to the narrow place - on the shortest path to the narrow passage between the shaft and the combustion chamber and is completely incinerated.

By supplying the heated waste and waste gas with fresh air at a temperature of at least 800 ° C before the narrow place, in a lower stoichiometric ratio, the waste is partially incinerated before the narrow place and the gasification of the waste is thereby intensified. The amount of fresh air supplied above the narrow place is so adapted to the amount of fresh air supplied directly in the narrow place that optimum combustion is achieved in the combustion chamber itself. Changing this ratio can easily control combustion. This makes it possible to reach a temperature of approximately 1500 ° C in the combustion chamber due to the large proportion of gas in the narrow place if a slag melt is desired.

3 143721

Also, the claim of claim 2 also contributes to ensuring efficient control of the combustion process, removing excess gas not necessary for the incineration of the waste from the incineration.

Such excess gas quantities may be used elsewhere as fuel gas. For incineration of difficult combustible waste, e.g. waste sludge, prior to the narrow site, the heated waste and the waste gas can be fed a combustion-promoting gas, e.g. methane-containing natural gas.

The invention also relates to an oven of the kind specified in the preamble of claim 3 for carrying out the method. The furnace is peculiar to the characteristic part of claim 3 *. Through the fresh air supply conduits opening above the narrow spot in the shaft, fresh air is introduced into the heated waste and into the waste gas in sub-stoichiometric proportions for partial combustion and degassing of the waste. As the combustion chamber's exhaust chamber encloses the central shaft, the waste in the shaft of the flue gas is heated in the extraction chamber so that no additional heating is required by means of separately supplied fuel such as oil. As the waste material in the shaft is kept in motion by means of the moving means, the waste is overturned and mixed in the shaft, thereby promoting the heating of the waste while the material in motion due to gravity is applied to the narrow place.

Finally, the claim as claimed in claim 4 serves to either withdraw part of the waste gas formed during the degassing of the waste so that this gas part is avoided by the combustion or to supply the combustion gas in cases where difficult combustible waste is to be incinerated.

In the following, the invention is explained in more detail with the aid of the drawing, which shows, partly from the side and partly in vertical section, an embodiment of the furnace for carrying out the method according to the invention. The furnace shown in the drawing has a central shaft 1 and a combustion chamber 3 located below it, which can be closed below by means of a flap 2, and which has a shaft 1 enclosing extractor space 3a. A tapered furnace muffle 4 terminates from below up to the shaft 1, while a tubular portion with a cone-shaped lower end portion 5 from above protrudes into the shaft. The tapered end portion 5 together with the furnace muffle 4 at the lower end of the shaft 1 * and at the transition to the chamber 3 form a narrow passage in the form of a ring slot, the width of which can be varied by the height-adjustable lower end portion 5 of the tubular share.

In the cavity of the end portion 5 is arranged a cone 6 which is so designed, dimensioned and positioned that it forms, together with the tubular part at the lower end of the latter, slots which are directed towards the narrow place, ie. the annular gap.

As shown in the drawing, the end portion 5 of the tubular member is coaxially surrounded by a tube so as to form a conduit or passage leading from the outside into the shaft 1 and in the lower part thereof 7 or on the said pipe there are bars 8 which project in the lateral direction. into the shaft-shaped compartments formed by the shaft 1 and the furnace muffle 4. In addition, on the inner wall of the shaft 1, there are pipes 9 »which with their upper ends protrude above the extractor compartment 3a and whose lower ends are located at the upper part of the furnace muffle 4.

In carrying out the method according to the invention, the shaft 1 is filled by means of a supply means 10 with waste approximately up to the height of the extraction chamber 3a. The fresh air is supplied directly to the narrow place and partly to the upper part of the shaft.

The fresh air introduced into the upper part of the shaft 1 does not pass through the tightly packed waste column, but via the pipes 9, in which it is heated, like the fresh air passing through the portion 5, into the lower part of the column, where this air causes a partial combustion and degassing of the waste material. . Thus, in the portion of the waste column located at the height of the pipes 9, the waste material is substantially airtightly enclosed but subjected to intensive drying and degassing because the central shaft 1 is heated by the hot flue gas flowing through the exhaust chamber 3a around the shaft.

When the combustion furnace is in thermal equilibrium, the portion 5 is set in a very slow rotating motion by means of a drive mechanism not shown in the drawing. Hereby, they carry rods 8 into the waste column carrying the waste material to prevent bridging and smearing zones in the material column. This facilitates the degassing process. By changing the rotational speed of the lot 5, you can also regulate the supply of waste to the narrow place.

Claims (2)

143721 5 Excess flue gas can be aspirated through the passage 7 as indicated by the arrows. However, through the conduit 7, the waste fuel gas can also be supplied. Unburning constituents falling on the ash bed here come into contact with the still oxygen-containing hot gas stream, thus burning these proportions fully. Continuous operation of the oven removes the ash from it in intervals of 1 to 2 days. Floating solids in the flue gas in the exhaust chamber 3a and solid particles entrained by the flue gas stream are deposited on filter mats 11 which are arranged at the outlet of the extractor compartment. These solids are also fully combusted here by the oxygen still present in the hot gas. The filter mats 11 are pressed from fibers of approximately 0.003 mm thickness and the mats have a thickness of approximately 10 to 15 mm. In a combustion furnace similar to the one shown in the ignition, a waste material consisting of animal carcasses, paper and moist leaves with a caloric content of approximately 1500 kcal / kg has been incinerated, whereby the furnace is kept in thermal equilibrium at a temperature above 1000 ° C in the combustion chamber. A process for combustion of waste, which is stored above a narrow space between a waste receiving shaft (1) and a combustion chamber (3) located immediately after the shaft and dried and degassed in the shaft by heating, whereby the resulting waste gas is incinerated in the combustion chamber. during supply of fresh air, and where, before the narrow place, the heated waste is supplied with fresh air, and in the narrow place the degassed waste is supplied with additional fresh air for incineration of the waste, characterized in that the waste is heated in the shaft under exclusion of air. said heated fresh air before the narrow site is fed to the waste gas and the degassed waste in a lower stoichiometric ratio and that the waste gas is drawn down through the narrow place.